Question about content

So, I finally got my personal statement rolling, but it contains a little bit of joking sarcasm. I'm wondering if this should be eliminated entirely, or if I can leave it in my statement. It isn't the main focus of the statement, and it's not offensive, but I've gotten the impression from Anna Ivey that it might not be well-received. I'm a pretty sarcastic person, so I feel like taking it out detracts from my statement as a reflection of myself. Thoughts?

In the beginning of my statement I'm running on a treadmill and talking about the various ways I distract myself from how badly it sucks. One of them includes observing this kid who always comes to the gym in shirts with the sleeves cut off and spends 50% of the time checking himself out in the mirrored wall where he lifts weights, so I'm kind of making fun of him. It's just a brief part of the story, which is basically going to be about how between junior and senior year I replaced all of my bad habits, academic and otherwise (exercise and diet, here), with more sustainable ones. How I stopped procrastinating and cramming for exams, which allowed me to spend 3 months self-studying for the LSAT, and how I stopped speed dieting, lost the 30, yes 30, pounds I gained freshman year, and now run 30 miles a week. All of this is going to relate to what caused this change, and how I think this has made me capable of handling whatever law school throws at me. So yeah, it's a few sentences just making a little bit of fun of this kid. What do you think?